Software Library Engineer, Blockstream

• The ideal candidate will combine strong technical skills with a collaborative mindset to ensure the project remains robust, efficient, and developer-friendly
• 5+ years of software development experience, with at least 3 years focused on C++ in complex, multi-component systems
• Experience with cross-language integration (e.g., C++ with Rust, Python, Java, or Swift)
• Familiarity with CMake, Docker, and CI/CD workflows
• Expert-level proficiency in C++ (modern standards, e.g., C++17/20)
• Strong understanding of systems programming, memory management, and performance optimization
• Knowledge of testing frameworks and writing robust unit/integration tests
• Exceptional problem-solving and debugging capabilities
• Clear communication skills for documenting code and collaborating with distributed teams
• Ability to manage priorities and lead technical initiatives

Desirable

• We are seeking an experienced Software Library Engineer, with deep expertise in C++ to lead the development and maintenance of the Green Development Kit (GDK), a vital software development kit for our bitcoin wallet apps
• This role focuses on the Core SDK (written in C/C++) while overseeing its integration with Rust modules, language wrappers (Java, Python, Swift), build systems (CMake, scripts, Docker), testing frameworks, and documentation
• Core SDK Development & Wrapper Integration (C/C++)
• Lead the development, maintenance and testing of the Core SDK, written in C/C++
• Debug complex issues, enhance performance, and ensure seamless integration with the Blockstream wallets and third party users
• Build System Contributions:
• Maintain and enhance CMake build files, build scripts, and Docker configurations to support C++ development and cross-component builds
• Resolve build-related issues and optimize for multiple platforms
• Publish regular releases incorporating new features, fixes and performance improvements
• Testing & Continuous Integration (CI):
• Develop and maintain C++-focused test cases within the testing suite
• Work with CI pipelines to validate Core SDK changes and their impact on downstream components
• Documentation
• Document C++ APIs, core functionality, and integration points for contributors and end-users
• Collaborate with the team to keep project-wide documentation current and accessible
• Collaboration with Mobile App Developers
• Partner with mobile app developers, the primary users of the GDK library, to understand their needs and ensure the Core SDK meets requirements for iOS (Swift) and Android (Kotlin) environments
• Provide technical support and guidance to app developers integrating the library into their applications